hey single cam ka guys got a massive fuel problem!!!!

[jesusno2]

Well first off a little info I'm using the stock hard lines that were on my wagon I cleaned them out made sure of that.so I hit the key fuel pump fires up, go to start crank, crank,crank and the motor is locking up now so I pulled the plugs and just smoke is bellowing out of the cylinders!!! And when it does start it runs so rich and just blows smoke and raw fuel out the exhaust. Now could this be caused but to small of a return line or do I have a pressure reg not working at all? I have my vaccumm sorce hooked up to the nipple coming right off the upper plenum. Here's a pic

[thisismatt]

Which is your return line?

[jesusno2]

In the pic its the line on the left. I used the vent line on the wagon as my return line.

[thisismatt]

Hmm - I suppose you could pipe the return soft line into a can to rule out the return line. Otherwise you kind of need a gauge to check the pressure in the feed line/fuel rail.

[jesusno2]

That's how it is now cause I have my tank out finishing up the sump I'm wondering if my return line being sumbmerged in fuel is a problem? Cause I dunno why its dumping so much fuel either my reg is bad or my vaccumm source is not good enough?

[datzenmike]

Isn't the return line usually larger than the inlet?? Could it be backwards, and if so could the regulator maybe not be able to lower the pressure? You may be running on full pump pressure...60-70 PSI?

[jesusno2]

It could be return bigger than inlet?? I dunno? I hooked the lines up backwards at first I wonder if that blew my reg out?

[fo0manchu]

I would first check fuel pressure. Then if pressure is good, check your fuel injectors. May have a stuck open injector or two.

[jesusno2]

That's a good idea I didn't know they could stick open! That would make sense why the engine just kinda stops cranking cause its just filling it full of fuel!

[fo0manchu]

The way I checked my fuel injectors was to just apply 12 volts to them directly(via a seperate harness of course) and they should make a clicking sound when powered. good luck

[jesusno2]

Checked the injectors their working FPR is working.Well I pulled codes from my ecu and its throwing a 41 code which does not give me a 41 code for the 240 at all but for the stanza and 200sx shows a air temp sensor and its also throwing a 12 code that says mass air meter malfunction. I'm confused on the air temp sensor as it does have one but the book does not give me a code for it which is weird

[jesusno2]

Insatalled a new maf but no change at all. filled it up with coolant also it fouled 3 plugs idleing yesterday lol! I'm thinking my tps is really shot and I'm pretty sure its taken out the 02 sensor also. That's the only thing that can be wrong sensor wise. Unless my ecu is bad which I do have another one of those also.

[icehouse]

You said you hooked up a noid light, if it's flashing fast it would seem the injectors are working fine. Aren't you running a walbro pump? I would run the return into a can, see how much fuel makes it past the regulator. There should be a good flow going past the regulator.

I've only ever hooked up 1 air temp sensor on a single cam KA and that was only because someone had it hooked onto the intake I ended up using on my truck so I figured why not

Have you tried running it with the TPS unplugged? Limp mode is usually pretty good on all Nissan EFI engines.

Another good test might be unplugging the fuel pump fuse while it's running, as the fuel pressure drops see if it runs decent before it dies. They run pretty long with no pump just from the pressure built up in the lines. Even then there might not be a long enough period of time to know if that's the problem. It would be fun to try never the less haha

I wish you where closer, I love trying to fix EFI problems

[jesusno2]

The car is running from a can on the ground right now. that fuse trick is a good idea although my pressure is good like 38 1/2 lbs the book shows 38 lbs for pressUre. The TPS I can't seem to figure out I can unplug it and it does nothing at all! Even twisting it around does nothing to affect the car.I need to get another one and a new 02 sensor.

[okayfine]

TPS isn't going to be your problem. KAs mainly look at the MAF to judge fuel addition.

Do you have the FSM for the year of your engine?

Where/how did you check for fuel pressure?

How have you determined that your TPS is bad? The FSM has the diagnostic process for determining a bad component.

FSM also will help you diagnose a bad MAF.

You likely have bad injectors. You could swap them with a known-good set.

Do you have a fire extinguisher near by when you're doing all this work?